The invention relates to lasers, and more particularly to a gas ion laser having an improved laser discharge tube, gas fill system and cooling system.
Gas ion lasers, such as argon lasers, have been constructed in a variety of ways. See, for example, U.S. Pat. Nos. 3,619,810, 3,760,213, 3,501,714, 4,376,328. The latter patent discloses a gas ion laser having a plasma tube or discharge tube formed of a non-precision ceramic cylinder with a large series of cup-shaped metal-conducting members spaced apart in the tube and expanded mechanically into contact with the internal surface of the ceramic tube prior to brazing. The cup-shaped members were assembled into the ceramic tube one by one using a floating mandrel through the ceramic tube, the tube being supported on a carriage on rails, so that the tube was moved back and forth over an expansion tool which placed each member into position in the ceramic tube and expanded its outer flange against the internal tube wall. Each of the cup-shaped members had attached to it, prior to assembly in the discharge tube, a cylindrical shield for gas isolation. A sputter-resistant tungsten disk with a central aperture was also placed on the floating mandrel, on the opposite side of the cup-shaped member from the shield, and when the entire assembly was brazed in an oven, the tungsten disks were simultaneously brazed to the heat webs. The patent emphasized the ability to use a non-precision formed ceramic tube because of the method used to bring the heat members into contact with the rough ceramic surface on the inside wall of the tube.
None of the various types of laser constructions of the prior art has had the advantages of the present invention described below, particularly in terms of elimination of destructive stresses in the ceramic tube wall, ease of and precision of assembly, dependability of brazing, efficiency in heating steps and gas fill, and efficiency of operation.